As farm sizes have increased over the years, agricultural implements have necessarily increased in size as well. Wider implements have been generally preferred as being more efficient for covering the increased areas, as opposed to using a plurality of smaller implements. Each implement also requires a relatively skilled operator, and same are not readily available in the sparsely populated rural areas.
Modern farms also typically include land that is scattered over a considerable area, requiring that implements be transported from one field to the next on public roads. In order to do so safely while allowing other traffic to pass, and in order move under overhead utility lines, it is generally considered that an implement in transport position should be no more than about 25 to 26 feet wide, and about 18 to 19 feet high.
In order to achieve this folded transport size in conventional implements comprising a center section and wing sections that fold vertically above the center section, implement size has been limited to about 64 feet. One typical configuration for folding a five section implement for transport is illustrated in U.S. Pat. No. 6,220,366 to Noonan et al. and U.S. Pat. No. 6,089,329 to Smith. The implement comprises a center section, an inner wing pivotally attached to each side of the center section, and an outer wing pivotally attached to outer ends of the inner wings. The outer wings are folded over to lie substantially flat above the inner wings, and then the inner wings are raised to an upright orientation such that the outer wings extend downward from the ends of the inner wings and between the inner wings. The inner wings in the Noonan implement are oriented substantially vertical, while those in the Smith implement lean somewhat inwards.
U.S. Pat. No. 6,092,609 to Jeffrey et al. illustrates an alternate configuration for folding a five section implement for transport where the outer wings are folded substantially vertical to the ends of the inner wings, and the inner wings are raised to a substantially vertical orientation with the outer wings oriented substantially horizontally and aligned end-to end.
The above implements provide 5 separate independent sections when working in the field. Each inner wing can pivot up and down with respect to the center section, and each outer wing can pivot up and down with respect to each inner wing. Such flexibility improves the ability of the implement to flex and follow ground contours to better maintain an even depth for the ground engaging tools typically mounted on the implement.
Such flexibility is not always required or provided, as for example in the implements illustrated in U.S. Pat. No. 6,684,962 to Lewallen and U.S. Pat. No. 6,761,228 to Dobson et al. The Lewallen and Dobson implements provide a three section implement when in the field working position, with a center section, and rigid right and left wing sections pivotable up and down with respect to the center section. In order to reduce the transport height however, instead of simply raising the wing sections to an upright orientation, each wing section folds for transport. As result, the Lewallen implement in transport has a five section transport configuration similar to that of the Jeffrey et al., while the Dobson implement has a five section transport configuration similar to that of Noonan et al. and Smith.
In the field position, the outer and inner wings of Lewallen and Dobson are locked together by linkage mechanisms such that they act as a single wing. The linkages are configured such that reduced force is required to be exerted by the hydraulic transport cylinders in order to maintain the inner and outer wings in alignment.
Implements wider than 64 feet are known where the implement is folded horizontally rearward or forward such that the wing sections trail behind or ahead of the center section, however such alternate configurations have their own design problems. For example it is typically required to pivot the rear end of the implement upward before pivoting the wings rearward or forward. Maneuvering the lengthy implement, and attaching air seeder carts and the like are problematic as well with such a departure from typical vertical wing lift designs.